/* 公共的样式 */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;

    background-image: url(../image/背景.png);
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
}

.nav {
    /*导航栏高度普遍是50px*/
    height: 50px;
    background-color: rgba(50,50,50,0.4);
    color: white;
    display: flex;
    justify-content: flex-start;
    align-items: center;
}
.nav .spacer {
    width: 70%;
}
.nav a {
    color: white;
    text-decoration: none;
    padding: 0 10px;
}
.container {
    width: 100%;
    height: calc(100% - 50px);

    display: flex;
    align-items: center;
    justify-content: center;
}